The rediscovery of the putative ant social parasite Manica parasitica syn. nov. (Hymenoptera: Formicidae) reveals an unexpected endoparasite syndrome.

Parasitism is ubiquitous across the tree of life, and parasites comprise approximately half of all animal species. Social insect colonies attract many pathogens, endo- and ectoparasites, and are exploited by social parasites, which usurp the social environment of their hosts for survival and reproduction. Exploitation by parasites and pathogens versus social parasites may cause similar behavioural and morphological modifications of the host. Ants possess two overlapping syndromes: the endo- and social parasite syndromes. We rediscovered two populations of the putative social parasite Manica parasitica in the Sierra Nevada, and tested the hypothesis that M. parasitica is an independently evolving social parasite. We evaluated traits used to discriminate M. parasitica from its host Manica bradleyi, and examined the morphology of M. parasitica in the context of ant parasitic syndromes. We find that M. parasitica is not a social parasite. Instead, M. parasitica represents cestode-infected M. bradleyi. We propose that M. parasitica should be regarded as a junior synonym of M. bradleyi. Our results emphasize that an integrative approach is essential for unravelling the complex life histories of social insects and their symbionts.

Machine Learning Approach for Muscovy Duck (Cairina moschata) Semen Quality Assessment.

This study aimed to develop a comprehensive approach for assessing fresh ejaculate from Muscovy duck (Cairina moschata) drakes to fulfil the requirements of artificial insemination in farm practices. The approach combines sperm kinetics (CASA) with non-kinetic parameters, such as vitality, enzyme activities (alkaline phosphatase (AP), creatine kinase (CK), lactate dehydrogenase (LDH), and γ-glutamyl-transferase (GGT)), and total DNA methylation as training features for a set of machine learning (ML) models designed to enhance the predictive capacity of sperm parameters. Samples were classified based on their progressive motility and DNA methylation features, exhibiting significant differences in total and progressive motility, curvilinear velocity (VCL), velocity of the average path (VAP), linear velocity (VSL), amplitude of lateral head displacement (ALH), beat-cross frequency (BCF), and live normal sperm cells in favour of fast motility ones. Additionally, there were significant differences in enzyme activities for AP and CK, with correlations to LDH and GGT levels. Although motility showed no correlation with total DNA methylation, ALH, wobble of the curvilinear trajectory (WOB), and VCL were significantly different in the newly introduced classification for "suggested good quality", where both motility and methylation were high. The performance differences observed while training various ML classifiers using different feature subsets highlight the importance of DNA methylation for achieving more accurate sample quality classification, even though there is no correlation between motility and DNA methylation. The parameters ALH, VCL, triton extracted LDH, and VAP were top-ranking for "suggested good quality" predictions by the neural network and gradient boosting models. In conclusion, integrating non-kinetic parameters into machine-learning-based sample classification offers a promising approach for selecting kinetically and morphologically superior duck sperm samples that might otherwise be hindered by a predominance of lowly methylated cells.

Revision of the species of the genus Diorchis Clerc, 1903 (Cestoda, Hymenolepididae) from rallid birds: a redescription of Diorchis acuminata (Clerc, 1902).

The type-species of the genus Diorchis Clerc, 1903, D. acuminata (Clerc, 1902) Clerc, 1903, is re-described and illustrated on the basis of the type-material from Fulica atra L. from the Middle Ural, Russia, and new specimens from the same host species from Bulgaria. Since the type-series consists of specimens of two species, a syntype is designated as lectotype. The main differentiating characters of D. acuminata are the diorchoid rostellar hooks, 36-39 µm long, with a foliate epiphyseal thickening of the guard; cirrus-sac of variable length, usually reaching and often crossing the midline of proglottis, occasionally reaching antiporal osmoregulatory canals; evaginated cirrus with cylindrical basal part, bulbous middle part and pipette-like distal part; compact vitellarium situated dorsally to the ovary; copulatory part of vagina with muscular poral and middle portions and an antiporal sac-like reservoir; elongate eggs with polar filaments on their envelopes. The type-specimens of D. ransomi Johri, 1939 and D. longibursa Steelman, 1939 from Fulica americana Gmelin from USA are also re-examined and illustrated. Based on the present results, D. ransomi and D. longibursa are recognised as synonyms of D. acuminata. The previous records of the species are discussed. Diorchis acuminata is recognised as a specific parasite of Rallidae (mainly species of the genera Fulica and Gallinula) in the Holarctic.

New cestode species of the genus Neoskrjabinolepis Spassky, 1947 (Cyclophyllidea: Hymenolepididae) from the Common Shrew (Sorex araneus L.) in Europe.

Neoskrjabinolepis (Neoskrjabinolepis) yanchevi n. sp. is described from common shrews Sorex araneus L. (Eulipotyphla: Soricidae) from Pirin Mts., Bulgaria (type-locality) and Russia (Arkhangelskaya Oblast'). The new species is characterised by ten rostellar hooks 37-40 µm long and possessing claw-like blades with crooked middle parts and well-developed epiphyseal thickenings of handles; a whip-shaped cirrus, 80-100 µm long, consisting of basal region with numerous small, rosethorn-shaped spines, and middle and distal regions armed with fine, needle-shaped spines; vagina provided with sphincter close to its orifice, with copulatory and conductive part not clearly distinct from one another; 40-50 eggs per gravid uterus. The species is differentiated from the remaining 4 species of the nominotypical subgenus of the genus Neoskrjabinolepis, which are parasites of the Palaearctic shrews of the genus Sorex.

Exploring parasites in extreme environments of high conservational importance: Artemia franciscana (Crustacea: Branchiopoda) as intermediate host of avian cestodes in Andean hypersaline lagoons from Salar de Atacama, Chile.

The hypersaline lagoons located in evaporation basins or salars (salt flats) in the Atacama Desert are extreme environments harbouring a specialised biota able to survive harsh conditions for life. The knowledge of the parasitic biodiversity of these extreme habitats is still scarce despite their functional importance in regulating relevant non-economic services like habitats of waterbirds. The present study is the first report on the cestode infection of Artemia franciscana Kellogg in Salar de Atacama lagoons in northern Chile. A total of 23 parasite larvae were isolated and identified as belonging to five cestode taxa of the order Cyclophyllidea: two species of the family Hymenolepididae, i.e. Flamingolepis sp. 1 and Flamingolepis sp. 2 (adults parasitic in flamingos); two species of Dilepididae, i.e. Fuhrmannolepis averini (adults parasitic in phalaropes) and Eurycestus avoceti (adult parasitic in charadriforms birds); and one species of Progynotaeniidae, i.e. Gynandrotaenia (?) stammeri (adult parasitic in flamingos). The cysticercoids of each species are described and figured. The study represents the first geographical record of the genera Eurycestus, Gynandrotaenia and Fuhrmannolepis in South America and the first report of Gynandrotaenia and Flamingolepis in A. franciscana in its native range. This survey also contributes to the knowledge of cestodes of Phoenicopteriformes and Charadriiformes and their life cycles in the Neotropical Region. A review of cestodes recorded in brine shrimps of the genus Artemia in the world is provided. Further studies on cestode fauna of aquatic birds and their intermediate hosts in hypersaline habitats of the Neotropical Region are needed to understand their functional role in such extreme and unique ecosystems.

Alien parasites on an alien fish species: monogeneans from the black bullhead Ameiurus melas (Siluriformes) in the Lake Srebarna Biosphere Reserve, Bulgaria, with the first record of Gyrodactylus nebulosus in the Palaearctic.

Black bullhead Ameiurus melas (Actinopterygii: Siluriformes) is an alien fish species of North American origin, which has expanded its invasive geographical range in Europe. In 2017-2019, 32 black bullhead specimens from the Lake Srebarna Biosphere Reserve, Bulgaria, were examined for monogenean parasites. Two species of monogeneans were recorded and identified on the basis of morphological and molecular data: Ligictaluridus pricei (Ancyrocephalidae), with prevalence 100% and intensity 2-32 (mean 13.3 ± 6.8), and Gyrodactylus nebulosus (Gyrodactylidae), with prevalence 72.0% and intensity 1-15 (mean 7.4 ± 4.3). Partial 18S rDNA and the ITS1 region of L. pricei were sequenced. For G. nebulosus, sequenced genes included the partial 18S rDNA and the entire ITS1-5.8S rDNA-ITS2 region as well as the mitochondrial COI gene. Both recorded monogenean species are specific parasites of North American ictalurid fishes and alien to Europe. The present study is the first record of L. pricei from Bulgaria and the first record of G. nebulosus from Europe and the Palaearctic Region.

Review of records of hymenolepidids (Eucestoda: Hymenolepididae) from dormice (Rodentia: Gliridae) in Europe, with a redescription of Armadolepis spasskyi Tenora & Barus, 1958 and the description of A. genovi n. sp.

Armadolepis (Armadolepis) spasskyi Tenora & Barus, 1958 is redescribed on the basis of the type-series consisting of the holotype from the garden dormouse Eliomys quercinus (Linnaeus) (type-host) and a paratype from the forest dormouse Dryomys nitedula (Pallas); the occurrence of this species in the fat dormouse Glis glis (Linnaeus) cannot be confirmed due to the lack of specimens from this host species both in the type-series and other studied samples. The main corrections in the diagnostic characters of A. spasskyi are related to the number and length of the rostellar hooks (12 hooks, 12-14 µm long versus 16-19 hooks, 15.3-17.1 µm long in the original description) and the position of the testes in triangle (versus in line as originally described). Specimens originally identified as Hymenolepis myoxi (Rudolphi, 1819) by Genov (1984) from the fat dormouse G. glis from Bulgaria are described as Armadolepis (Bremserilepis) genovi n. sp. The new species differs from the congeners by the presence of a rudimentary rostellum and rudimentary rostellar hooks; the new species differs from the other two species of the subgenus, A. (B.) myoxi and A. (B.) longisoma, by its longer cirrus-sac (196-240 µm), scolex diameter of 180-300 µm (wider than that of A. myoxi and narrower than that of A. longisoma) and wider ovary (220-310 µm). Cestodes previously reported as Hymenolepis myoxi from E. quercinus from Switzerland and France (western and north-western Alps) are now identified as Armadolepis (A.) jeanbaeri Makarikov, 2017. Cestodes from G. glis from Switzerland and Slovakia, previously identified as Hymenolepis sulcata (von Linstow, 1879), are now identified as Armadolepis (B.) myoxi (sensu stricto). The position of Hymenolepis (s.l.) sciurina Cholodkovsky, 1913 as a subspecies of A. myoxi is rejected and it is considered a species inquirenda.

Pan-European Study on the Prevalence of the Feline Leukaemia Virus Infection - Reported by the European Advisory Board on Cat Diseases (ABCD Europe).

Feline leukaemia virus (FeLV) is a retrovirus associated with fatal disease in progressively infected cats. While testing/removal and vaccination led to a decreased prevalence of FeLV, recently, this decrease has reportedly stagnated in some countries. This study aimed to prospectively determine the prevalence of FeLV viraemia in cats taken to veterinary facilities in 32 European countries. FeLV viral RNA was semiquantitatively detected in saliva, using RT-qPCR as a measure of viraemia. Risk and protective factors were assessed using an online questionnaire to report geographic, demographic, husbandry, FeLV vaccination, and clinical data. The overall prevalence of FeLV viraemia in cats visiting a veterinary facility, of which 10.4% were shelter and rescue cats, was 2.3% (141/6005; 95% CI: 2.0%-2.8%) with the highest prevalences in Portugal, Hungary, and Italy/Malta (5.7%-8.8%). Using multivariate analysis, seven risk factors (Southern Europe, male intact, 1-6 years of age, indoor and outdoor or outdoor-only living, living in a group of ≥5 cats, illness), and three protective factors (Northern Europe, Western Europe, pedigree cats) were identified. Using classification and regression tree (CART) analysis, the origin of cats in Europe, pedigree, and access to outdoors were important predictors of FeLV status. FeLV-infected sick cats shed more viral RNA than FeLV-infected healthy cats, and they suffered more frequently from anaemia, anorexia, and gingivitis/stomatitis than uninfected sick cats. Most cats had never been FeLV-vaccinated; vaccination rates were indirectly associated with the gross domestic product (GDP) per capita. In conclusion, we identified countries where FeLV was undetectable, demonstrating that the infection can be eradicated and highlighting those regions where awareness and prevention should be increased.

First report of cestode infection in the crustacean Artemia persimilis from Southern Chilean Patagonia and its relation with the Neotropical aquatic birds.

The brine shrimp genus Artemia Leach (Crustacea, Branchiopoda), a keystone group in hipersaline wetlands all over the world, offers an excellent model to study species interactions (parasitism) and to explore "hidden fauna" (avian endoparasites). The present study is the first report on the parasite infection of the South American species Artemia persimilis from the Southern Chilean Patagonia (50°S-53°S). Samples were collected in Los Cisnes and Amarga lagoons, the two most austral populations of this crustacean described to date, during two seasons (spring and autumn). A total of 98 larvae of cestodes of the family Hymenolepididae (Cestoda, Cyclophyllidea) were found and identified as belonging to the following taxa: Confluaria podicipina (adult parasitic in grebes), Flamingolepis sp. (a cestode parasite of flamingos), Fimbriarioides (?) sp. (adults of the species of this genus infect waterfowl and shorebirds) and Wardium sp. (definitive host unknown, most probably charadriiform birds). This is a new geographical record of C. podicipina and the genus Fimbriarioides for the Neotropical Region, the latter being the most widely distributed species at both localities and seasons surveyed, and the only species recorded in autumn (April). Cestode community composition in Los Cisnes population was characterised by dominance of Flamingolepis sp., representing more than 65% of the total cestode species recorded, whereas in the Amarga population the most abundant parasite (>83%) was Fimbriarioides (?) sp. Significant seasonal variations were detected in Los Cisnes lagoon for Flamingolepis sp. and C. podicipina, with exclusive presence of them in spring (November). Besides providing novel information on cestodes infection in A. persimilis, this study provides new data on the life cycle of cestodes of Neotropical aquatic birds such as South American flamingos and grebes. Our finding expands the knowledge on the biodiversity and population dynamics of extreme and unique environments from high latitudes (Patagonia) and makes evident the need of further taxonomical and ecological studies for better understanding the life cycles of avian helminth parasites in the Neotropics and the role of aquatic invertebrates in them.

Massive infection of a song thrush by Mesocestoides sp. (Cestoda) tetrathyridia that genetically match acephalic metacestodes causing lethal peritoneal larval cestodiasis in domesticated mammals.

BACKGROUND: Peritoneal larval cestodiasis induced by Mesocestoides Vaillant, 1863 (Cyclophyllidea: Mesocestoididae) is a common cause of severe infections in domestic dogs and cats, reported also from other mammals and less frequently from birds. However, there is a limited knowledge on the taxonomy of causative agents of this disease. RESULTS: In the present study, we investigated a massive, likely lethal, infection of a song thrush Turdus philomelos (Passeriformes: Turdidae) by Mesocestoides sp. tetrathyridia. We performed combined morphological and phylogenetic analysis of the tetrathyridia and compared them with the materials obtained previously from other birds and mammals. The metrical data fitted within the wide range reported by previous authors but confirmed the limited value of morphological data for species identification of tetrathyridia of Mesocestoides spp. The molecular analyses suggested that the isolates represented an unidentified Mesocestoides sp. that was previously repeatedly isolated and sequenced in larval and adult forms from domestic dogs and cats in Europe, the Middle East and North Africa. In contrast to the present study, which found encysted tetrathyridia, four of the five previous studies that identified the same species described infections by acephalic metacestodes only. CONCLUSIONS: The tetrathyridia of the examined Mesocestoides sp. are described in the present study for the first time. However, the possible match with the species that were previously reported to infect birds remains uncertain. The phylogenetic analyses also suggested the rejection of two cases that were previously identified as Mesocestoides corti as they were likely caused by the same species as in the presently reported infection case. The newly provided DNA sequences should allow the assignment to species in the future, when adults of the genus Mesocestoides are more thoroughly sequenced.

Two new cestode species of the family Hymenolepididae Perrier, 1897 (Cyclophyllidea) from passerine birds in Ethiopia, with the erection of Citrilolepis n. g.

Two new cestode species of the family Hymenolepididae Perrier, 1897 are described from birds of the order Passeriformes at Wondo Genet, Ethiopia. Passerilepis zimbebel n. sp., a parasite of Terpsiphone viridis (Müller) (Monarchidae), is distinguished from its most similar congeners by its diorchoid rostellar hooks with length 37-38 µm, its median ovary consisting of three compact lobes, its compact vitellarium and the variable position of the terminal genital ducts passing mostly dorsally to the poral osmoregulatory canals. Citrilolepis n. g. is erected as monotypic for C. citrili n. sp., a parasite of Crithagra citrinelloides (Rüpell) (Fringillidae). The new genus is distinguished from the remaining avian and mammalian genera of the family Hymenolepididae by the presence of numerous (18) rostellar hooks, unilateral sinistral genital pores, ventral osmoregulatory canals with transverse anastomoses, 3 (rarely 4, in c.10% of proglottides) testes in number with variable positions in the proglottis and the sac-like uterus not extending beyond the osmoregulatory canals.

Mitochondrial genome of Paruterina candelabraria (Cestoda: Paruterinidae), with implications for the relationships between the genera Cladotaenia and Paruterina.

The taxonomic concept for the family Paruterinidae is controversial, especially concerning the position of the genus Cladotaenia, since the latter genus has been placed sometimes in other families, i.e. in the Taeniidae or in the distinct family Cladotaeniidae; finding a solution based on morphological data is difficult and molecular data on paruterinids and related groups are scarce. In this study, the complete mitochondrial (mt) genome sequence of the type-species of the type-genus of the Paruterinidae, Paruterina candelabraria, was determined and annotated. Gene arrangements are identical with those of Cladotaenia vulturi but differing from those of species of the family Taeniidae by the order change between tRNA-SerUCN and tRNA-LeuCUN. Phylogenetic tree was constructed by Bayesian Inference (BI) analysis using the concatenated amino acid sequences of 12 protein-coding genes. The analysis clearly shows that the Paruterinidae and Taeniidae are sister-groups, and Cladotaenia is a sister taxon of Paruterina. This supports the position of the genus Cladotaenia in the family Paruterinidae and reveals the necessity for sequencing additional taxa of the Paruterinidae for better understanding of phylogenetic relationships within the group.

Phylogeny of hymenolepidid cestodes (Cestoda: Cyclophyllidea) from mammalian hosts based on partial 28S rDNA, with focus on parasites from shrews.

The aims of the study are to enrich the partial 28S rDNA dataset for hymenolepidids by adding new sequences for species parasitic in the genera Sorex, Neomys and Crocidura (Soricidae) and to propose a new hypothesis for the relationships among mammalian hymenolepidids. New sequences were obtained for Coronacanthus integrus, C. magnihamatus, C. omissus, C. vassilevi, Ditestolepis diaphana, Lineolepis scutigera, Spasskylepis ovaluteri, Staphylocystis tiara, S. furcata, S. uncinata, Vaucherilepis trichophorus and Neoskrjabinolepis sp. The phylogenetic analysis (based on 56 taxa) confirmed the major clades identified by Haukisalmi et al. (Zool Scr 39:631-641, 2010) based on analysis of 31 species: Ditestolepis clade, Hymenolepis clade, Rodentolepis clade and Arostrilepis clade; however, the support was weak for the early divergent lineages of the tree and for the Arostrilepis clade. Novelties revealed include the molecular evidence for the monophyly of Coronacanthus, the non-monophyletic status of Staphylocystis and the polyphyly of Staphylocystoides. The analysis has confirmed the monophyly of Hymenolepis, the monophyly of hymenolepidids from glirids, the position of Pararodentolepis and Nomadolepis as sister taxa, the polyphyly of Rodentolepis, the position of Neoskrjabinolepis and Lineolepis as sister taxa, and the close relationship among the genera with the entire reduction of rostellar apparatus. Resolved monophyletic groups are supported by the structure of the rostellar apparatus. The diversification of the Ditestolepis clade is associated with soricids. The composition of the other major clades suggests multiple evolutionary events of host switching, including between different host orders. The life cycles of Coronacanthus and Vaucherilepis are recognised as secondarily aquatic as these taxa are nested in terrestrial groups.

Bird cestodes from Huinay (Comau Fjord), Chilean Patagonia: several species of the family Dilepididae (Platyhelminthes, Cyclophyllidea), with the erection of two new genera.

Birds in the Huinay area, Los Lagos region, Chile, were studied for parasites. Here we report 2 new genera and species of the family Dilepididae (Cyclophyllidea) found in common local passerines: Janinelliapeebeehi gen. n., sp. n. was found in Elaeniaalbiceps (Tyrannidae) and Huinaylepiselegans gen. n., sp. n. was found in Aphrasturaspinicauda (Furnariidae). Other dilepidid parasites are reported for the first time from Xolmispyrope (Tyrannidae) and from 2 species of Rhinocryptidae. Cotylorhipissureshi Jadhav & Shinde, 1981 is considered a species inquirenda. The very high diversity and endemism of the observed cestode fauna in the Valdivian temperate rain forests is noted.

Avian haemosporidians from rain forests in Madagascar: Molecular and morphological data of the genera Plasmodium, Haemoproteus and Leucocytozoon.

The diversity of the haemosporidian genera Plasmodium, Haemoproteus and Leucocytozoon in birds from rain forests in Madagascar is characterized combining techniques of PCR and microscopy and based on the examination of 72 host individuals of 23 species in 15 families. High total prevalence of haemosporidians (68%) is detected, with Leucocytozoon infections being predominant (59.7%) and lower comparable prevalence of Plasmodium (18.0%) and Haemoproteus (23.6%) infections. Using mitochondrial cytochrome b (cytb) marker, 23 genetically distinct lineages are identified: 9 of Plasmodium spp., 6 of Haemoproteus spp. and 8 of Leucocytozoon spp. Fifteen of all lineages have not been reported by previous studies. This study provides the first data on haemosporidian morphological and molecular diversity found in the endemic families Vangidae and Bernieriidae. Two haemoproteid species, Haemoproteus fuscae Mello and Fonseca, 1937 and H. killangoi Bennett and Peirce, 1981, are redescribed based on the present samples and linked to the cytb lineages hCELEC01 and hZOSMAD01, respectively. Phylogenetic analysis is performed to test the relationship of the discovered new lineages with parasites from closely related avian hosts suggesting that multiple colonisation of hosts by haemosporidian parasites has occurred on the island.

Description of Acuaria europaea n. sp. (Spirurida: Acuariidae) from Dendrocopos syriacus (Hemprich & Ehrenberg) and Oriolus oriolus (L.) (Aves) in Europe, with results of re-examination of related European species of Acuaria Bremser, 1811.

Acuaria europaea n. sp. is described from one Dendrocopos syriacus (Hemprich & Ehrenberg) (Piciformes: Picidae) (type-host) and three Oriolus oriolus (L.) (Passeriformes: Oriolidae) in Bulgaria (type-locality) and France. The new species is characterised by cordons extending slightly beyond the level of the anterior end of the glandular oesophagus, left spicule 297 µm long, right spicule 155 µm long, protruding vulvar region and strongly ventrally curved female tail. The male (holotype) and the female (allotype) of A. parorioli Chabaud & Petter, 1961 from O. oriolus are regarded as not being conspecific based on the differing morphology of their cordons; the female is identified as A. europaea n. sp. The type-material of Acuaria attenuata (Rudolphi, 1819) is redescribed. The species is characterised by a small and delicate body, cordons extending beyond the oesophago-intestinal junction and similar spicules in size and shape, 140 µm long. The only type-material of Acuaria anthuris (Rudolphi, 1819) available for examination consists of a male and a female (syntypes) from O. oriolus. The two specimens differ from one another by the relative lengths of their cordons and we consider them as belonging to two species. However, both type-specimens differ in their much shorter cordons from the species of Acuaria parasitising Corvidae. The present study reveals that the original description of A. anthuris has been based on heterogeneous material.

Morphology and molecules reveal the alien Posthodiplostomum centrarchi Hoffman, 1958 as the third species of Posthodiplostomum Dubois, 1936 (Digenea: Diplostomidae) in Europe.

Metacercariae of two species of Posthodiplostomum Dubois, 1936 (Digenea: Diplostomidae) were subjected to morphological and molecular studies: P. brevicaudatum (von Nordmann, 1832) from Gasterosteus aculeatus (L.) (Gasterosteiformes: Gasterosteidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Perca fluviatilis L. (Perciformes: Percidae), Czech Republic (morphology, cox1, ITS1-5.8S-ITS2 and 28S); and P. centrarchi Hoffman, 1958 from Lepomis gibbosus (L.) (Perciformes: Centrarchidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Slovakia (cox1 and ITS1-5.8S-ITS2). In addition, cercariae of P. cuticola (von Nordmann, 1832) from Planorbis planorbis (L.) (Mollusca: Planorbidae), Lithuania (morphology and cox1) and metacercariae of Ornithodiplostomum scardinii (Schulman in Dubinin, 1952) from Scardinius erythrophthalmus (L.) (Cypriniformes: Cyprinidae), Czech Republic, were examined (morphology, cox1, ITS1-5.8S-ITS2 and 28S). These represent the first molecular data for species of Posthodiplostomum and Ornithodiplostomum Dubois, 1936 from the Palaearctic. Phylogenetic analyses based on cox1 and ITS1-5.8S-ITS2, using O. scardinii as the outgroup and including the three newly-sequenced Posthodiplostomum spp. from Europe and eight published unidentified (presumably species-level) lineages of Posthodiplostomum from Canada confirmed the distinct status of the three European species (contrary to the generally accepted opinion that only P. brevicaudatum and P. cuticola occur in the Palaearctic). The subspecies Posthodiplostomum minimum centrarchi Hoffmann, 1958, originally described from North America, is elevated to the species level as Posthodiplostomum centrarchi Hoffman, 1958. The undescribed "Posthodiplostomum sp. 3" of Locke et al. (2010) from centrarchid fishes in Canada has identical sequences with the European isolates of P. centrarchi and is recognised as belonging to the same species. The latter parasite, occurring in the alien pumpkinseed sunfish Lepomis gibbosus in Europe, is also supposed to be alien for this continent. It is speculated that it colonised Europe long ago and is currently widespread (recorded in Bulgaria, Slovakia and Spain); based on the cox1 sequence of an adult digenean isolate from the Ebro Delta, Spain, only the grey heron (Ardea cinerea L.) (Ciconiiformes: Ardeidae) is known to be its definitive host in Europe.

The first data on the vitellogenesis of paruterinid tapeworms: an ultrastructural study of Dictyterina cholodkowskii (Cestoda: Cyclophyllidea).

The present study provides the first ultrastructural data of the vitellogenesis in a cestode species of the cyclophyllidean family Paruterinidae, aiming to expand the limited data on the vitellogenesis in cyclophyllidean cestodes and to explore the potential of ultrastructural characters associated with vitellogenesis for phylogenetic and taxonomic studies of this order. The process of vitellocyte formation in Dictyterina cholodkowskii follows the general pattern observed in other tapeworms but exhibits several specific differences in the ultrastructure of vitelline cells. The vitellarium contains vitellocytes at various stages of maturation. The periphery of the vitellarium and the space between maturing vitellocytes are occupied by interstitial cells. Differentiation into mature vitellocytes is characterized by high secretory activity, which involves the development of granular endoplasmic reticulum, Golgi complexes, mitochondria and vitelline globules of various sizes. During vitellogenesis, the progressive fusion of these globules results in the formation of two large membrane-limited vitelline vesicles that eventually fuse into a single large vesicle. Mature vitellocytes are composed of a single vitelline vesicle, a high content of cytoplasmic organelles and have no nucleus. No traces of lipid droplets and glycogen granules are detected in the cytoplasm of mature vitellocytes, which might be related to biological peculiarities of this family, i.e. the release of eggs into environment within the tissues of the paruterine organ, which may serve as a source of nutrients for embryos.

Morphological and molecular identification of Gyrodactylus bubyri Osmanov, 1965 (Monogenea: Gyrodactylidae) from Caucasian dwarf goby, Knipowitschia caucasica (Berg) (Actinopterygii: Gobionellidae) from a Black Sea lagoon.

Gyrodactylus bubyri Osmanov, 1965, a monogenean parasite of Caucasian dwarf goby Knipowitschia caucasica (Berg) described from Aral Sea and subsequently reported from the same host from Strymon River, Greece, is recorded from Atanasovsko Lake, Bulgarian Black Sea coast (the first record of G. bubyri from the Black Sea basin). The species is redescribed by light and scanning electron microscopy as well as the ITS rDNA sequence is obtained. As comparative materials, specimens of G. bubyri from K. caucasica (Strymon River), G. charon Vanhove and Huyse in Vanhove et al., 2014 from Knipowitschia milleri (Acheron Delta, Greece) and G. micropsi Gläser, 1974 from Potamoschistus microps from North Sea (Belgium) are studied. Comparative morphology and molecular data demonstrate that G. micropsi is a junior synonym of G. bubyri (new synonymy). The validity of G. charon is questioned, pending examination of additional materials in order to prove it as a distinct species or as a junior synonym of G. bubyri.